Stem Cells in Adult and Embryo

Question 1

What was the result of taking a blastomere from a sea urchin embryo at the 2 cell stage?

Answer 1

Became smaller but normal larva

Question 2

Define totipotency

Answer 2

Can differentiate into embryonic and extra-embryonic cell types

Question 3

Define pluripotency

Answer 3

Can differentiate into any of 3 germ layers

Question 4

Define multipotency

Answer 4

Can differentiate into multiple closely-related cells

Question 5

Define unipotency

Answer 5

Can differentiate into only one cell type

Question 6

What are the factors controlling neurogenesis?

Answer 6

Modes of division and cell cycle length - cell cycle regulators
Transcription factors
Epigenetic factors
Diffusible signals

Question 7

What is symmetric division of a neural progenitor?

Answer 7

Vertical cleavage

Proliferative

Question 8

What is asymmetric division of a neural progenitor?

Answer 8

Horizontal cleavage

Neurogenic

Question 9

What is symmetric terminal division of a neural progenitor?

Answer 9

Vertical cleavage

Neurogenic - 2 neurons made

Question 10

What is the effect of Notch?

Answer 10

Keeps progenitor in undifferentiated state

Question 11

What is the effect of cell cycle lengthening?

Answer 11

More cortical progenitors

Question 12

What is the effect of cell cycle shortening?

Answer 12

More self-renewing divisions

Question 13

What is Nestin a marker for, and when is it seen?

Answer 13

Neural stem cells

3 hours

Question 14

What is Tuj a marker for, and when is it seen?

Answer 14

Cells that become neurons

3 days

Question 15

What is GFAP a marker for, and when is it seen?

Answer 15

Cells that become astrocytes

10 days

Question 16

What is O4 a marker for?

Answer 16

Oligodendrocytes

Question 17

Name 2 intrinsic transcription factors differentially activated by external factors controlling neurogenesis

Answer 17

Pax6

Nkx2.2

Question 18

What are the types of stem cells and what are their properties?

Answer 18

Adult - pools of multipotent SCs in certain tissues
Embryonic - pluripotent SCs in blastocyst
Induced - reprogrammed somatic cells

Question 19

Where are new neurons generated in the adult brain and where do they migrate to?

Answer 19

SVZ of lateral ventricles

Through rostral medullary stream - to olfactory bulb - become interneurons

Question 20

What do radial glial-like cells in the SVZ of the adult brain become and where do they migrate to?

Answer 20

Transient amplifying cells - become neuroblasts

Through tube formed by astrocytes - to olfactory bulb - become interneurons

Question 21

Where in the adult hippocampus does neurogenesis occur?

Answer 21

Subgranular zone (SGZ) in dentate gyrus

Question 22

What is the process of neurogenesis in the SGZ?

Answer 22

Radial and non-radial precursors become immediate progenitors - become neuroblasts - migrate to inner cell layer - become dentate gyrus granule cells

Question 23

How can the effect of a novel enriched environment on neurogenesis be shown?

Answer 23

Inject BrdU into adult mice - label for newborn neurons

More BrdU+ neurons in mice exposed to novel enriched environment

Question 24

What are the Yamanaka factors and how are they used?

Answer 24

Oct3/4, Sox2, Klf4, c-Myc

Generate iPS cells from human dermal fibroblasts

Question 25

What are some functional tests of vision restoration in mice?

Answer 25

Synapse formation - electron microscopy
Cell responses to light - patch clamping
Visually-evoked visual cortex activity - intrinsic cortical imaging

Question 26

What are some behavioural tests of vision restoration in mice?

Answer 26

Visual responses - optokinetic head tracking

Vision - water maze

Question 27

What are the difficulties in repairing end stage retinal degeneration?

Answer 27

Loss of supporting cytoarchitecture
Re-wiring of remaining neurons
Scarring
Immune reaction